Synthesis of microporous nano-composite (hollow spheres) for fast detection and removal of As(V) from contaminated water

Abstract

Simple synthesis of hollow-wagon-wheel sorbent (with CA/CTAB sacrificed template). • High surface-area microporous hollow spheres of silica@Mo(VI) for As(V) sorption. • Pseudo-first order rate and Sips equations for modeling kinetics and isotherms. • Used as naked-eye sensor, the material detects As(V) at level as low as 0.3 µM. • Efficient As(V) desorption using 1 mM NaOH solution and high recycling performance.

Cubically cage-shaped mesoporous ordered silica for simultaneous visual detection and removal of uranium ions from contaminated seawater

“…The detection range (DR), the limit of detection (LOD), and the limit of quantification (QOD) of U(VI) ions with the use of the HOM-OCBBG sensor/captor were estimated from the linear part of the calibration plot based on the following eqs. (1&2) [10];…”

“…The stability constant (log Ks) of the formed [U-L] n+ complex at a specific pH value significantly affects the uranyl ion-selectivity of the fabricated sensor/captor, particularly at low metal ions concentration compared with competitive matrices. The value of log KU(VI) can be calculated using the following equation: log KU(VI) = [ML]S/ [L]S× [M], where [M] refers to the concentration of free unreacted uranyl ions, [L] represents the concentration of the organic ligand attached to the inorganic carrier and S refers to species in the solid phase [10,32]. The results from the binding constants (log KU(VI)) of the complex formed upon addition of uranyl ions of 6.75 at pH 3.4, indicating that the O/N-containing ligand binds strongly to the U(VI) ions onto the sensor/captor surface.…”

“…Chemosorption techniques are at the forefront of the large-scale removal methods while detecting radionuclides is dominated by instrumental spectroscopic methods, such as Raman, atomic absorption, and atomic emission spectroscopy. There are, however, recent interest in the development and design of chemical sensors for the detection and quantifying radionuclides in natural water that offer good sensitivity, short response times, and selectivity [7][8][9][10][11][12]. Unfortunately, most sensors developed so far were kinetically slow with limited sensitivity, and the materials used to fabricate the sensor are different from those used for the removal.…”

Towards the Nano-future to Deal with Metal and Metalloid Contamination

“…The use of adsorbent in nano-form enhances their surface area for more efficient metal(loid) adsorption and increases the speed of the remediation process (Siddiqui et al, 2019;Wong et al, 2017). However, sometimes NPs may agglomerate that may affect the lifetime of NP based filters and reduce their efficiency with time (Dutta et al, 2020;Zaid et al, 2020). Therefore, NPS-based water remediation also needs more research and optimization in the coming years (Leus et al, 2018).…”

Geogenic arsenic removal through core–shell based functionalized nanoparticles: Groundwater in-situ treatment perspective in the post–COVID anthropocene

“…The aggregarted and structurally unstable NPs finally leach into an aqueous medium. These leached NPs require sophisticated instrumentation facilities to separate out from the drinking water source such as groundwater aquifer after their application ( Dutta et al, 2020 ; Zaid et al, 2020 )…”